I'm getting in on this shit *cracks knuckles* I have a few different prompts I may post. Some may be all out story ideas.
This one is a mash-up of multiple prompts and fanfics I have read.
So basicly, the accident left Danny with a ton of issues, both mentally and physically. He stutters sometimes, has a few mobility issues, and sometimes he just aches so bad he can't get out of bed. That mixed with the slow heartbeat, shallow breathing, and pale skin of a halfa, he almost seems like one hella sick kid.
His secret gets revealed and instead of his parents hurting him they just tell him to leave and never come back (i love a good vivisection fic, but i personally like to imagine they can't bring themselves to do it). Danny kinda becomes homeless and lives in his car for a bit. He eventually (somehow) learns he is adopted and goes to find his birth parents.
His dad is... you guessed it! Bruce Wayne! He goes to confront him with multiple forms of evidence and Bruce just SHUTS DOWN. He rejects Danny (probably out of fear and regret for not being there for him, again this is based on multiple prompts). Danny, degected, goes back to live in his car. Unbeknownst to him though, the bat kids had been listening in and decided to make Danny part of their family one way or another. So they try everything to get him to stay in Gotham.
Eventually they start to notice the 'medical' issues, they learn of the accident, and see that his grades and attendence in school dropped. Naturally, as any bat clan member does, they connect the dots and think "holy shit, this kid is dying and he just wanted to know his birth family"
Now everyone is pissed at Bruce for rejecting him, Bruce feels worse and and hides away MORE, and Danny is wondering why his step siblings are suddenly far sweeter, but also more protective and worried about him.
"Danny was born a Wayne" AU except he's Bruce's grand uncle. The result of a one time drunken affair, shortly before Kenneth Wayne's death, to a young unmarried woman who gave the baby up for adoption.
(Whether the Fenton's, and therefore Amity, were just ahead of their times or the DC timeline is shifted a bit so that DP happens in its cannon era is up to you. Dealers choice, though now that i know about her i just love badass widowed prohibition leader Laura Elizabeth Wayne)
Danny grows up knowing hes adopted and loved by the Fentons but something (dealer's choice) happens and he loses his family and friends (maybe the whole town goes too?). In an attempt to avoid a Dan situation he flees into the Infinite Realm and doesn't stop.
He just wanders, time passes in its weird Realms way, not that Danny truly notices. A protector spirit thats lossed everything it protected. Its a wonder he doesn't fade and he actually might've if it wasn't for his human side.
But its a tug at his core that brings him from his near catatonic wandering. Gone before he can even understand it but enough to shake him back to himself. Enough to know that hes nowhere near ready to go anywhere familiar so he continues on, his wandering no less pointless but at least he's aware again.
What feels like a relatively short time later he gets another tug, and this time he manages to follow it.
He follows it invisibly through a natural portal that drops him somewhere in New Jersey and all the way to a fancy hospital room in the gloomiest city he's ever seen.
In there he sees his half brother Patrick Wayne, though he wont figure out their connection for a few more years, holding little Agatha. She's adorable in her little dress and pigtails and her sweet face causes that familiar tug he recognizes from what must have been six years ago given the girls age.
Then a nurse comes in and hands a little bundle to what must be the mother (whos name i cant find) and Danny takes one look at the little core tugger who brought him here and just melts. Even without knowing yet that this is his last remaining family, his instincts latch on and he vows to protect and care for the Waynes.
And he does.
He finds his forgetful brother's documents and keeps Aggy company when everyone else is busy and soothes baby Thomas so his poor sister-in-law can get some more sleep. He ices fevers and bruised knees and helps on later games of hide and seek.
He very rarely becomes visible and only to the children. His grief over the Fenton's convinces him its better to protect his new family from the shadows.
Danny explores every inch of the manor, including secret passages and an underground cave system. He claims a forgotten room in the back of the attic as his own, which over the years fill up with knickknacks, heirlooms, and pictures of the family. Even a gift or two from Agatha, who hadn't stopped believing in their shadowy guardian like her brother did when Danny felt they were too old to see him without drawing suspicion.
The manor becomes his haunt and he always knows where each family member is within it. And when any guests have some no good intentions.
And when baby Bruce is born tugging at his core and with the bluest little eyes, he welcomes the fussy little thing. And makes sure dear Martha never knows just how fussy baby Bruce really is, otherwise she might've never had a full nights sleep.
Danny blames himself for not being there when Thomas and Martha die, and promises to never leave Bruces side, practically becoming the boy's living shadow. Watching over him as he gets older, secretly aiding him in his training. Danny feels a bit of pride when Bruce takes some inspiration from the old stories Thomas told him of the shadowy Wayne family protector when creating his Batman identity, glad his nephew still remembers him even if he hasn't shown himself since the now young man was six.
Danny continues to protect and care for the family in a variety of ways over the years even as the family grows.
Lightening Alfred's workload, softening Dick's falls, calming Jason's temper both pre and post pit, hiding Tim's coffee when the boy hasn't slept in far too long, providing plenty of shadows and hiding nooks for Cass, helping Damian hide the litter of kittens he found.
And no one seems to know he's there, except maybe Cass and he's pretty sure Alfred has been know since he first started working for the family. No one knows, that is, until Duke Thomas moves in and lookes right at him watching invisibly from the sidelines.
(@omnicrafts @dcxdpdabbles @hdgnj @ailithnight @nelkcats @im-totally-not-an-alien-2 i dont know, the main point of all this is that Danny's been protecting the Wayne family for decades and no one, except maybe Alfred, knew until Duke moved in)